(1) Field of the Invention
The present invention relates to an imaging material and more particularly, to a diazo imaging material for imaging multicolor images utilizing a plurality of infrared rays having different wavelengths.
(2) Description of the Prior Art
Recording systems such as electron photography, electrostatic recording, current application recording, heat-sensitive recording, ink jet, etc. have been hitherto known as those for forming multicolor images. Further, much research as been conducted to develop recording system utilizing microcapsules, and various systems such as a pressure sensitive recording system, a heat-sensitive recording system and so on have already been invented. A number of patents concerning such recording system are disclosed, for example, in U.S. Pat. Nos. 4,399,209, 4,440,846, 4,501,809, 4,621,040 and so on.
U.S. Pat. No. 4,399,209 is directed to a transfer imaging system which comprises a layer of microcapsules wherein a chromogenic material is encapsulated with a photosensitive composition. The photosensitive composition comprises a radiation-curable composition which upon exposure causes an increase in its viscosity thereby preventing diffusion of the chromogenic material upon rupture of the capsule. Upon rupture of the capsules, those capsules in which the radiation-curable material is not activated will release the chromogenic material which will transfer to a developer sheet and react with the developer material to form the image. Similar imaging systems, i.e., a so-called self-contained imaging sheet wherein the developer and the photosensitive encapsule are carried on a single substrate, is described in U.S. Pat. No. 4,440,846.
A color imaging system employing the aforementioned photosensitive composition encapsulated in pressurerupturable microcapsules is described in British Pat. No. 2113860.
British Pat. No. 2113860 discloses a photosensitive material useful in full color imaging comprising a support having on the surface thereof microcapsules which individually contain cyan, magenta and yellow color formers and photosensitive compositions having distinctly different sensitivities. A uniform mixture of the microcapsules is distributed over the surface of the support. Images are formed by separating the red, green and blue components of the image to be reproduced and translating these components into different wavelengths of actinic radiation to which the photosensitive compositions are distinctly sensitive. The photosensitive material is image-wise exposed to the translated radiation and thereafter it is subjected to a uniform rupturing force, such as pressure, which causes the microcapsules in the underexposed and unexposed areas to rupture and release the color formers. The color formers then react with a developer material which is contained on the same or a different support and produce a full color image.
In these conventional techniques, the ink jet method involves a problem of clotting and is not sufficiently reliable, the other recording methods require many complicated steps for recording the three primary colors repeatedly from a CRT, etc. In particular, since the conventional recording material using capsules coloration recording is carried out by reacting one coloring component incorporated in capsules with the other coloring component present outside the capsules through the rupture of capsule walls caused by applied pressure, a pressure roll which has a force of 200-400 pounds per linear inch to break the capsules is needed.